Revolutionising Sewerage Treatment

As a leading pump manufacturer and distributor in Australia, Kelair provides clients with a range of world renowned, high quality products, supported by knowledgeable staff. We recently installed at a central Queensland mine, the Blivet is a low energy, high performance system that is installed easily, is straightforward to run and quickly turns effluent into usable irrigation water. The simple and efficient system is revolutionising their sewage treatment.

Small footprint

The Kelair-Blivet is a stand-alone packaged sewage treatment plant that can be installed quickly and with minimum civil works.

Its space-saving dimensions make it one of the most compact designs available worldwide.

With a footprint of only 10.9m x 2.27m, the BL4000 can treat up to 400EP at 230L/EP/day and 55gBOD/EP/day.

The cost and space-effective Blivet aerotor provides 1.5 times the surface area of a traditional RBC and this, combined with the utilisation of parallel plates, equates to an excellent and unmatched population treatment ratio.

With individual models suitable for populations from 30 to 400 people, multiple units can be run in parallel to meet the requirements for even larger individual applications.

Easy to install and transport

As a modular unit, the Blivet design is completely adaptable to suit a variety of applications.

This capability also lends itself to future expansion or relocation.

Kelair Pumps General Manager Myro Bratkovic said that the Blivet is fully portable, fully packaged, and completely contained.

“Once the civil work has been completed, the components are easily installed by contractors on-site,” he said.

“Each piece of the system is supplied by Kelair - the tanks, the pumps, the pipework and the valves – along with detailed drawings for installation.”

Multiple units can be installed in a staged manner to cater for increased demand, such as the arrival of construction crew as a project expands, maintenance shut-downs, or the discovery of a new ore body.

They can equally as simply be removed piece by piece when the project winds down.

“When the system is no longer needed, the entire package can be put on a truck, transported to a completely new site and easily installed for the next job,” Mr Bratkovic said.

Adding discrete modular units permits phased development in step with the project growth.

For ease of transport by road, rail or sea, the components all fit comfortably within standard container size dimensions.

The compact pre-fabricated and portable package makes the unit suitable for temporary or permanent installation on existing or greenfield sites and easily removable for re-siting.

It is suitable to be fitted in buildings, construction sites, housing developments and areas not connected to municipal sewerage mains.

The Blivet can be added as an adjunct to an existing works, or as a discrete system in conjunction with primary settlement and humus tanks of separate supply, such as concrete tanks.

Kelair is able to be on site to supervise the installation when required.

Kelair also supplies the control system panel, which is can be built to the specific customer requirements.

Construction

The construction of the tankage from steel reinforced GRP (Glass Reinforced Polyester) makes it impervious to decomposition in the most demanding environments.

GRP is a composite material system consisting primarily of a plastic resin matrix with glass fibre reinforcement.

It is non-corrosive, strong, lightweight, maintenance free, and can be erected efficiently and economically.

It is stronger than concrete, steel and aluminium and is naturally watertight.

Per unit weight, GRP is among the strongest commercial materials available.

Contaminate-free landscape

The low-emission design makes the Blivet suitable for environmentally sensitive sites.

“The Blivet provides a clean solution to waste-water and ensures that rehabilitation of the mine at the end of life is minimal,” Mr Bratkovic said.

“Water ways and the ground remain uncontaminated, minimizing the clean-up process in the future.”

Meeting these standards has many benefits to mining companies including in terms of ESG, obtaining licenses for further exploration or new mine sites.

How it works

A major advantage of the system is that it does not need ancillary tankage or equipment to produce high-quality final effluent from raw, unsettled sewage.

The Kelair-Blivet comprises primary settlement sludge storage, aeration via the aerotor drum system, an aerobic zone, and final settlement (humus tank).

Primary settlement consists of temporarily holding the sewage in a quiescent (state of dormancy) basin where heavy solids can settle to the bottom while oil, grease and lighter solids float to the surface.

“The raw effluent enters the primary settlement tank. It then flows into the Aerotor which comprises various quantities of rotating drums, similar in style to rotating paddle steamer style wheels, half submerged, moving at 6RPM,” Mr Bratkovic said.

“The active bacteria growing on and inside the drums consume the biological material in the sewage as it passes through.

“The use of bacteria eliminates harmful chemicals, creates a clean effluent exiting the tank and ensures that the environment remains unharmed.”

Aerobic bacteria utilises dissolved oxygen or air in the, sewage and is a cleaner way to treat than anaerobic bacteria, which digest the waste through acid fermentation.

The treatment of the waste happens within a few short hours as compared to a septic process using anaerobic digestion, which can be in the order of 70 to 90 days, depending on temperature.

Aerobic digestion or activated sludge is formed through aeration of the incoming sewage, where it is mixed with the previously grown deposit of so-called humus known as a bacterial biomass.

This is where digestion of nutrients and ammonia takes place.

“The resulting discharge is then treated with chlorine to remove any e coli.

The rotating drums in the Aerotor section provide a small amount of pumping action, and gravity is also utilised to transfer the effluent through the system, exiting at the back end of the Aerotor where it drops into the humus tank.

From here the treated effluent either gravitates or is pumped to the storage area and from there is used for irrigation.

“The simplicity of the system is the key to its success,” Mr Bratkovic said.

“Low power use and simple installation makes this an attractive system, especially for remote locations.”

Tertiary treatments such as effluent, disinfection, and media filtration are available as options.

Energy-saving

The Blivet system reduces energy costs in sewerage treatment for mining companies, by combining the best features of existing rotating biological contactor (RBC) technology with the additional advantage of active aeration.

The distinction is that the Blivet operates without the use of blowers, making it not only simpler but also cheaper and cleaner to run.

“The Kelair-Blivet uses minimal power making it well suited to being powered by a battery pack and either wind turbine or solar panel,” Mr Bratkovic said.

The largest model of a Blivet, the BL4000, requires only a 0.75kW geared motor for the Aerotor which operates continuously and a 0.55kW humus pump which operates for 2min/hr.

Discreet

Placed above ground or buried to deck level, the Blivet can be installed discreetly and unobtrusively into the landscape, eliminating the presence of unsightly open tanks or lagoons.

Sealed with locked GRP lids at ground level, noise and odours are contained.

As the unit does not use a blower system, operational noise is kept to a minimum.

The waterproof GRP lids also remove any problem of attracting flies and other pests and reduce external noise intruding on village accommodation, especially for shift workers.

Simple to operate

The Blivet is very popular in PNG and similar extreme remote locations as it is easy to install, operate and uses minimal power.

It is also simple to operate. Specialist operators are not required, as all maintenance and running tasks can be performed by general maintenance staff.

The units can also be equipped with telemetry for remote monitoring, eliminating the requirement for constant manning.

This is an example of a mining company taking its stewardship of the land seriously and working with the farmers to benefit both leaseholders and the environment and leaving the land in prime condition.

The Kelair-Aerotor Biozone is available as a separate unit in a range of standard modular sizes.